The binary compound monocalcium aluminate (CaO.Al2O3, abbreviated as CA) is a clinker in the calcium aluminate cement, which comprises about 40-50% of essential minerals, has a quite high activity, and characterized by normal settling and rapid hardening, thus being a main source of strength of the calcium aluminate cement. The hydration reaction of monocalcium aluminate and the products obtained therefrom vary considerably with temperature. When the temperature is lower than 20° C., the hydration product is CAH10; when the temperature is in the range of from 20 to 30° C., the hydration product includes CAH10, C2AH8, and AH3; and when the temperature is higher than 30° C., the hydration product consists of C3AH6 and AH3. The hydration products CAH10, C2AH8 and other crystalline calcium aluminate hydrates (with a hexagonal platelet morphology) are in a metastable phase, and can spontaneously convert into a finally stable product C3AH6, accompanying with the formation of a large amount of free water. The conversion is accelerated with increasing temperature. The C3AH6 crystal has a cubic crystal system, which has a cubic crystalline form, and has a (packed) structural strength far lower than that of CAH10 and C2AH8. Furthermore, the formation of water causes the internal pores to increase, such that the structural strength is decreased. Therefore, the long-term strength of the calcium aluminate cement declines somewhat and generally by a factor of 40 to 50%, which leads to a serious impact in a hot and humid environment, and even causes the structural deterioration. As a result, the calcium aluminate cement generally cannot be used in structural engineering.
As a new bone repair and substitute material, the calcium phosphate cement receives great attention and becomes a focus of research and application in the art of clinical tissue repair, due to its good biocompatibility, osteoconductivity, biosafety, capability of arbitrary shape formation, and low heat release during the hardening process. However, the use of calcium phosphate cement in a variety of areas is limited by the defects such as slow hydration and hardening, and inadequate mechanical performances. The essential mineral tricalcium phosphate (Ca3P2O8, 3CaO.P2O5, or TCP) in the calcium phosphate cement has a quite slow hydration rate at normal temperature to 60° C., and the hydration can be accelerated only at a certain temperature, so as to give a high-strength, highly durable hydration product.